Dipolar spin-waves and tunable band gap at the Dirac points in the 2D magnet ErBr3

Magnonic devices, based on the physics of spin-waves, are a potential alternative to process and store information that consume less energy and van der Waals crystals are candidate materials for such applications. Here, the authors investigate the magnetic ground state and spin-wave spectrum of ErBr3 finding that the dipolar interactions play a dominant role and allow for continuous control of topological excitations.